The present invention concerns roller mills of the type which have been used for many years to crack or crimp grain, such as oats or corn. It is particularly concerned with the crimping of oats but makes provision, also, for cracking corn. The material to be cracked or crimped is gravity fed into the nip between a pair of opposed rollers which are spaced from each other by a distance selected in accordance with the material being handled which is such that the granular material has its shell cracked, but the grain itself is not unduly crushed or pulverized. This cracking and flattening of the outer shell, in the case of oats, for example, makes the oats more readily digestable by horses and it is estimated that a horse obtains the same amount of nutrition from one pound of oats which have been so cracked, as it would from up to one and one-half pounds of oats which have not been processed in this manner.
Because the objective of such mills is to crack or rupture the outer shell of the material without unduly crushing the material inside, the spacing between the two rollers must be related to the size of the grains or kernels of the material being cracked. Oats, for example, require a much smaller spacing than corn.
The prior art discloses various devices for adjusting the spacing between rollers of mills of the general type under discussion, see, for example, Hesse Pat. No. 3,208,677 and Glaser Pat. No. 2,144,841. However, the prior art spring adjustment mechanisms tend to be unnecessarily complex and do not operate positively in a manner which assures a precision operation in which most of the oats passing through are crimped.
The present invention is especially directed to a high capacity, heavy duty crimper having precision mechanism for accommodating the shifting of the axis of one roller toward and away from the axis of another roller which is of a simple, but positive acting construction which accurately maintains the axes of the two rolls in parallelism during such movement and the cam locks them in a particular relative position.
A further object of the invention is to design an oat crimper which can be readily fine tuned, and in which the operator is automatically aware when the proper nip for oat crimping is achieved and cannot narrow the nip beyond that spacing to a spacing which would unduly crush and damage the oats being processed. Still a further object of the invention is to provide a roll crimper having precision for positively assuring crimping, while, also, providing the versatility to process corn, and then oats in succession, and to process any remnant kernels of corn, and the versatility to remove any foreign object which might inadvertently reach the rollers.